Rot-resistant finish for textile materials



United States Patent r 3,317,345 ROT-RESISTANT FINISH FOR TEXTILE MATERIALS Linton Avery Fluck, Jr., and Philip B. Roth, Bridgewater Township, Somerset County, and William Norio Nakajima, Somerville, N.J., assignors to American Cyanamid Company, Stamford, Conn., a corporation of Maine No Drawing. Filed June 25, 1963, Ser. No. 290,295

Claims. '(Cl. 117138.5)

This invention relates to a process for treating textile materials to impart a rot-resistant finish thereto and to the textile material characterized by said rot-resistant finish. More particularly, this invention relates to a process for treating celulosic or cellulose containing textile materials to impart rot resistance thereto and to such textile materials characterized by said finish.

As is well known, cellulosic textile materials, when finished with aminoplasts such as melamine-formaldehyde condensates to impart shrinkage control and wrinkle recovery thereto, normally achieve some rot resistance, though it be of a low order of magnitude. When such textile materials are finished in a conventional manner, in addition to achieving wrinkle resistance, shrinkage control and a minor degree of rot resistance, the tensile strength of the material is nearly always adversely affected.

Current procedures for rendering cellulosic textile materials rot resistant with little or no tensile strength loss, include the treatment of the textile material with certain water-soluble arninoplasts and curing catalysts or accelerators therefor, followed by curing the aminoplast in a moist atmosphere, preferably at room temperature. See US. Patent No. 2,763,574.

While such processes are highly effective in imparting rot resistance to cellulose containing textile materials, such procedures are time-consuming and expensive, due to the long periods of time required to cure the aminoplasts, which holding or curing time constitutes an additional step which is a departure from that typically employed in the finishing of cellulose containing textile materials.

Other methods of obtaining rot-resistant cellulosic textile materials involve the application of various metal soaps or salts such as those of mercury, cobalt and copper. Typically, copper naphthenate and copper 8-quinolinolate have been employed for this purpose. Metal soaps frequently have definite and objectionable odors and produce discolorations on the textile materials finished therewith. Each of these objectionable properties limit their use.. In some instances, such compounds require the use of expensive and even toxic solvents if they are to be applied readily and in most instances the rot resistance imparted by such compounds is not durable to leaching and/or exposure to sunlight.

Therefore, there exists a need in the textile finishing .industry to provide a durable rot-resistant finish for cellulose containing textile materials which can be applied by employing conventional equipment and conditions, which finish does not adversely affect such original characteristics of the textile material as strength and color.

Therefore, it is an object of the present invention to provide a process for imparting a durable rot-resistant finish to cellulose containing textile materials, which process is readily adaptable to equipment and conditions normally employed in the conventional finishing of I ,cellulose textile materials to impart wrinkle resistance and shrinkage control thereto, which process in addition does not significantly adversely affect the strength or color of the finished textile materials.

It is'a further object of this invention to provide cellulose containing textile materials characterized by durable rot resistance, the color and strength of which are not significantly adversely affected relative to the unfinished materials.

These and other objects and advantages of the present invention will become more apparent from the detailed description thereof set forth hereinbelow.

In accordance with the present invention, a method is provided for imparting a rot-resistant finish to cellulose containing textile materials which comprises applying thereto a water-soluble aminoplast, a compound selected from the group consisting of thiourea and urea and a catalytic amount of a water-soluble aluminum salt of a strong mineral acid. Thereafter, the aminoplast is cured at a temperature of from about 200 to 400 F.

:By the expression cellulose containing textile material or cellulose textile material and similar expressions as they are employed herein, it is meant fabrics, whether they be knitted, woven, felted or otherwise formed, composed of a major portion of fibers of cotton, rayon, jute, ramie, hemp and the like. Preferably, a cellulosic textile material consists of cellulosic fibers and in particular cottom fibers, although blends of such. fibers with noncellulosic materials such as polyester fibers, acrylic fibers, silk and the like are contemplated, although such blends should contain at least 50% of cellulosic fibers.

The Water-soluble aminoplasts are preferably the water-soluble etherified methylol melamines or melamine-formaldehyde condensates such as bis(methoxymethyl)melamine, tris-(methoxymethyl)dimethylol melamine, hexakis(methoxymethyl)melamine and the like. Suitable water-soluble etherified methylol melamines may be prepared by condensing melamine and formaldehyde in amounts so as to combine from 1 to 6 moles of formaldehyde per mole of melamine and subsequently reacting the me-thylol compound with a suitable alcohol to prepare the water-soluble etherified derivatives. Suitable alcohols include the saturated aliphatic alcohols, such as methyl, ethyl and the like, glycols such as ethylene glycol, glycol ethers and other alcoholic compounds capable of condensing with the methylol group present on the melamine to form water-soluble products. Suitable alcoholic compounds may be condensed with the methylol groups on the melamineon a mole-per-mole basis.

The water-soluble etherified methylol melamine is applied in an amount of from between about 2% to about 50% solids based on the dry weight of the cellulose containing textile material and preferably is applied in an amount of from between 5% and about 20% solids based on the dry weight of such textile material.

While for many purposes urea and thiourea are considered to be equivalent, this is not true in the present invention in that urea that has been demonstrated to be inferior to thiourea in the process thereof. This will be demonstrated more clearly hereinafter wherein it will be demonstrated that the rot resistance achieved with thiourea is surprisingly more durable than that achieved with urea. The reason for the difference between urea and thiourea in accordance with the process of this invention is not fully understood, but may well be the result of the selection and employment of specific catalysts which have been demonstrated to be unique in the present process. Employing such catalysts, the true merits of this invention become readily apparent.

The use of the thiourea or urea, among other things, functions to limit tensile strength losses, is in amounts of from between 1%- and about 10% based on the dry weight of the fabric and preferably is employed in an amount of from about 1.3% to about 7.5% based on the dry weight.

The catalysts employable in the process of this invention are the water-soluble aluminum salts derived from strong acids such as nitric acid, hydrochloric acid and sulfuric acid. Such salts include aluminum nitrate, alumium chloride and aluminum sulfate, which salts may be employed singly or in combination with each other. In accordance with this invention, aluminum chloride is the preferred catalyst.

The catalysts are employed in amounts of from between .25% and 15% solids based on the solids of etherified methylol melamine employed and preferably in amounts of from between 1% to about based on the weight of such resin solids.

In accordance with the present invention, the watersoluble etherified methylol melamine and the thiourea or urea and curing accelerator may be applied to the textile material by spraying, coating, immersion, padding or other conventional procedures.

After application, the textile material may be dried at temperatures of from about 200 F. to about 250 F. and cured at temperatures of from about 200 F. to about 400 F. or the material may be dried and cured in a single operation.

Drying or drying and curing times are dependent upon the type of fabric treated and the temperature employed. Thus, for light-weight fabric, drying may be accomplished at from 0.5 to about 3 minutes and curing at from 1 to about 3 minutes time. Drying and curing in one operation may be done at times ranging from 1.5 to 5 minutes, also dependent upon the substrate treated and the temperature employed. The drying and curing may be accomplished in conventional drying and curing equipment employed by textile finishers to impart wrinkle resistance and shrinkage control to cellulosic textile materials.

In order to more fully illustrate the present invention, the following examples are given primarily by way of illustration. No specific details or enumerations contained therein should be construed as limitations on the present invention except insofar as they appear in the appended claims. All parts and percentages are by weight unless otherwise specifically designated.

In the comparative data presented hereinaftter, the soil burial tests, a measure of rot resistance, were carried out in accordance with the Tentative Test Method 301957T set forth in the American Association of Textile Chemists and Colorists Technical Manual of 1962.

The tensile strength measurements reported were carried out on a Scott Tensile Tester in accordance with standard A.S.T.M. methods.

EXAMPLE 1 To 80 x 80 cotton percale swatches were applied the following treatments.

Treatment:

(A) 7.5 solids (owf) bis(methoxymethyl)-methylol melamine 1.0% solids (owr) aluminum chloride (anhydrous) (B) Same as A plus 6.7% solids (owf) urea (C) Same as A plus 6.7% solids (owf) thiourea (owf) :on weight of fabric (owr) =on weight of resin The swatches were passed through their respective treatments, squeezed on a micro-set padder, then dried at 225 F. for 2 minutes followed by curing at 350 F. for 1.5 minutes.

A portion (1 inch warp strip) of each treated swatch plus an untreated swatch were tested initially for tensile strength, while another portion of each treated plus an untreated swatch were tested after 2 weeks soil burial.

Results are shown in Table I.

TABLE I Initial Tensile Tensile Strength Strength After Soil Burial Treatment of Fabric Percent Loss Percent Loss Lbs. Due to Lbs. Due to Treatment Burial Treatment A containing no additive (no thiourea or urea) resulted in 25% loss of initial strength, whereas both treatments B and C wherein urea or thiourea were used as additives resulted in little or no loss of initial strength. However, after soil burial testing it can be seen that thiourea is superior to urea in the present in vention.

EXAMPLE 2 To swatches of greige cotton, 11-oz. duck were applied the following treatments.

Treatment:

(A) 10% solids of (owf) bis(methoxymethyl) methylol melamine 1.0% solids (owr) aluminum chloride (anhydrous) 1.0% (owb) surfactant 1 (B) Same as A plus 5% solids (owf) urea (C) Same as A plus 5% solids (owf) thiourea (owb)=on weight of bath.

The swatches were passed through their respective treatments, squeezed on a micro-set padder, then dried for 4 minutes at 225 F. followed by curing at 350 F. for 3 minutes.

The treated swatches were then given a process wash containing a detergent plus sodium carbonate followed by rinsing and drying.

A portion (1 inch warp strip) of each treated swatch plus an untreated swatch were tested initially for tensile strength; other portions were subjected to 4, 8 or 12 weeks soil burial after which they were also tested for strength.

Results are shown in Table II.

TABLE II Initial Tensile Tensil Strength After Soil Strength Burial Treatment of Fabric Percent Loss 4 wks., 8 wks., 12 wks., Lbs. Due to lbs. lbs. lbs.

Treatment Treatment A with no additive resulted in a 27% initial tensile loss with poor resistance to rotting :after 8 weeks Iburial. Treatments B and C show some initial loss, with the urea additive having a slight advantage over the thiourea. However, urea as an additive aiforded protection to rotting through only 4 weeks burial, whereas the treatment containing thiourea as the additive did not lose any strength even after 12 weeks of burial.

EXAMPLE 3 1 Condensation product of nonyl phenol plus ethylene oxide (9.5 mole) based on total weight of treating bath,

Treatment-cntin ued (B) Same as A plus solids (owf) thiourea (C) 7.5% solids (owf) bis(methoxyme-thyl)methylol melamine (D) Same as A substituting 12% magnesium chloride (owr) for the aluminum chloride.

The swatches were treated in the same general manner as described in Example 2.

Sohds alummum chlorlde (anhy' 5 Portions of each treated swatch plus an untreated drolls) swatch were process washed in a solution containing de- (D) Same as C plus 5% sohds (owf) th1ourea t t d di bon te,

1.0% of the Surfa ta t lidenflfied i Example Tensile tests on 1 inch warp strips were performed based on the total bath welght was used in all initially and after 8 weeks soil burial. treatments. 10 Results are shown in Table IV.

TABLE IV Tensile Strength Treatment of Fabric Catalyst Used After 8 Weeks Soil Burial Initial, lbs.

Lbs. Percent Loss Aluminum Chl0ride 112 106 5.0 Ammonium Sulfate. 96 63 37. 0 Zine Nitrate 107 88 18.0 D Magnesium Chloride 97 55 41. 0 Untreated 119 0 100. 0

The treated swatches were treated in the manner described in Example 2 with the exception that no process wash was used.

Table IV demonstrates that superior durable rot resistance is achieved only with the catalyst of this invention.

Portions of the treated swatches and an untreated EXAMPLE 5 swatch were leached in cold water for 24 hours and comparison tests made on swatches that were not leached. In Order to further demonstrate the uniqueness of ap- Results are shown in Table III. pl1cants catalyst in the impartatlon of rot resistance to TABLE III Unleaehed Tensile Strength After Soil Burial Leached Tensile Strength After Soil Burial Treatment of Fabric 16 wks., 16 wks, 16 Wks., 16 wks, Init., lbs. 8wks, lbs. lbs. percent In1t.,lbs. 8wks.,lbs. lbs. percent Loss Less the treatment is quite durable to water leaching.

EXAMPLE 4 Comparison of catalysts To swatches of greige cotton, 11 oz. duck were applied the following treatments.

cellulosic textile materials, aluminum chloride was compared with other accelerators well known in the textile finishing industry, which accelerators were employed in conventional amounts.

In the comparison, 80 x 80 bleached cotton percale was finished so as to apply 7%, based on the dry weight of the material, of methylated trimethylol melamine, 5% thiourea on the same basis, and the accelerators in the amounts indicated based on the weight of the resins. All fabric was dried for one minute at 225 F. and cured for one minute at 325 F. The cured samples were process washed, rinsed through running warm water, squeezed Treatment: and dried at 225 F.

(A) 13% solids (owf) bis (methoxymethyl)methylol The results of this comparison are set forth in Table V melamine below.

TABLE V Treatment (solids on fabric) Tensile Strength After Initial Warp Tensile 3 Weeks Soil Burial Strength (lbs) Average of 5 cut 1" warp breaks Resin Accelerator Lbs. Percent Loss 1 7.0% methylated trimethylol 1% aluminum chloride 53 27 49 melamine+5% thiourea. 2 d 3.5% dlammonium phosphate. 54 12 78 3 1.0% zinc chloride 53 14 74 5% solids (owf) thiourea 1.0% solids (owr) aluminum chloride (anhydrous) (B) Same as A substituting 3.5% ammonium sulfate (owr) for the aluminum chloride (C) Same as A substituting 10% zinc nitrate (owr) for the aluminum chloride Table V above demonstrates that the rot-resistant finish of this invention is a minimum of about 33% better than that accomplished using other well-known aminoplast curing accelerators under standard conditions.

We claim:

1. A method for imparting a rot-resistant finish to cellulose containing textile materials which comprises applying thereto based on the dry weight of the material, from 2 to 50% of a water-soluble aminoplast, 1 to of a compound selected from the group consisting of thiourea and urea, and a catalytic amount of a watersoluble aluminum salt of a strong mineral acid, and thereafter curing the aminoplast at a temperature of from about 200 F. to about 400 F.

2. Rot resistant cellulose containing textile material prepared according to the process of claim 1.

3. A method for imparting a rot-resistant finish to cellulose containing textile materials which comprises applying thereto based on the dry weight of the material, from 2 to 50% of a water-soluble etherified methylol melamine, 1 to 10% thiourea and a catalytic amount of a Water-soluble aluminum salt of a strong mineral acid and thereafter curing the etherified methylol melamine at a temperature of from about 200 F. to about 400 F.

4. A method for imparting a rot-resistant finish to cotton containing textile materials which comprises applying thereto based on the dry weight of the material, from 2 to 50% of a water-soluble methylated methylol melamine, 1 to 10% of thiourea and a catalytic amount of a water-soluble aluminum salt of a strong mineral acid, and thereafter curing the methylated methylol melamine at a temperature of from about 200 F. to about 400 F.

5. A method for imparting a rot-resistant finish to woven cotton fabric which comprises applying thereto based on the dry Weight of the material, from 2 to 50% of a water-soluble methylated methylol melamine, 1 to 10% of thiourea and a catalytic amount of aluminum chloride, and thereafter curing the methylated methylol melamine at a temperature of from about 200 F. to about 400 F.

6. A method for imparting a rot-resistant finish to rayon fabric which comprises applying thereto based on the dry weight of the material, from 2 to 50% of a watersoluble methylated methylol melamine, 1 to 10% of thiourea and a catalytic amount of aluminum chloride, and thereafter curing the methylated methylol melamine at a temperature of from about 200 F. to about 400 F.

7. A method for imparting a rot-resistant finish to cellulose containing textile material which comprises applying thereto, based on the dry weight of the material, from 2 to of a water-soluble aminoplast, about 1 to 10% of thiourea, and a catalytic amount of a water-soluble aluminum salt of a strong mineral acid, and thereafter curing the aminoplast at a temperature of from about 200 F. to about 400 F.

8. A method for imparting a rot-resistant finish to cellulose containing textile material which comprises applying thereto, based on the dry weight of the material, from 2 to 50% of a methylated methylol melamine, about 1 to 10% of thiourea, and a catalytic amount of aluminum chloride, and thereafter curing the methylated methylol melamine at a temperature of from about 200 F. to about 400 F.

9. A method for imparting a rot-resistant finish to cellulose containing textile material which comprises applying thereto, based on the dry weight of the material, from 5 to 20% of a water-soluble aminoplast, about 1.3 to 7.5% of thiourea, and a catalytic amount of a watersoluble aluminum salt of a strong mineral acid, and thereafter curing the aminoplast at a temperature of from about 200 F. to about 400 F.

10. A method for imparting a rot-resistant finish to cellulose containing textile material which comprises applying thereto, based on the dry weight of the material, from 5 to 20% of a methylated methylol melamine, about 1.3 to 7.5% of thiourea, and a catalytic amount of aluminum chloride, and thereafter curing the methylated methylol melamine at a temperature of from about 200 F. to about 400 F.

References Cited by the Examiner UNITED STATES PATENTS 1,867,035 6/1932 StOcker 117137 X 2,339,203 1/1944 Stregler et al. 117-139.4 2,456,568 12/1948 Scott et al 117139.4 X 2,529,856 11/1950 West et al.

2,763,574 9/1956 Ruperti 117-1385 3,084,071 4/1963 Van Loo et al. 1l7143 3,197,270 7/1965 Roth 117138.5 X

WILLIAM D. MARTIN, Primary Examiner.

T. G. DAVIS, Assistant Examiner. 

1. A METHOD FOR IMPARTING A ROT-RESISTANT FINISH TO CELLULOSE CONTAINING TEXTILE MATERIALS WHICH COMPRISES APPLYING THERETO BASED ON THE DRY WEIGHT OF THE MATERIAL, FROM 2 TO 50% OF A WATER-SOLUBLE AMINOPLAST, 1 TO 10% OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THIOUREA AND UREA, AND A CATALYTIC AMOUNT OF A WATERSOLUBLE ALUMINUM SALT OF A STRONG MINERAL ACID, AND THEREAFTER CURING THE AMINOPLAST AT A TEMPERATURE OF FROM ABOUT 200*F. TO ABOUT 400*F. 